I have a trailer, less than a year old, and the reverse solinoid seems to be stuck. I dont know this for sure, but with the fill lid off the reservoir, and pumping the cylinder, there is a stream of fliud that blows into the reservoir. There is very little brake at the trailer wheels. I thought the brakes might need to be bled, but that doesnt appear to be the problem.

Its still under warranty, so well see what happens come Monday.

Dealer said to check the solinoid while running out from neutral to reverse (solinoid should be actuating - clicking). Hopefully this is the problem, otherwise, I guess its going to him for repairs.

Heritage trailer? The reverse solenoid on my Heritage trailer has a bypass the directs fluid back to the reservoir. Every other trailer I have owned had no bypass. The solenoid simply blocked fluid from going to the lines. Anyway, mine went bad and did what yours is doing - directing the fluid back to the reservoir. Simple enough to replace.

Ok, that eases my mind - I worried that maybe the seals were blown on the cylinder piston. It's a Loadrite / 5Starr

If you have a jump box use that with some jumper wires. Makes it a little easier. Put the ground wire on your harness to negative and when you put the positive side to the solenoid wire you should hear it click.

I had the wife put the tranny in forward/reverse, and I can here the solenoid kicking back and forth. I broke the fitting off the solenoid to see how much fluid is working through the line on a cycle, and hardly any fluid is going through the valve (im thinking its partially stuck, because i wouldnt be getting a squirt back into the reservoir if not, and, actually, there is more fluid being returned to the reservoir than going down the line circuit, like a 1:5 ratio, or less).

Sounds like the solenoid, right???

Well, i eliminated the solenoid from the system. Brakes wont pump up, and attempts at bleeding the lines are fruitless - almost no fluid is getting to the bleed screw. I would assume at this point that the piston seals are toast in the master cylinder. I have an email with a short video in to the trailer manufacturer, as well as the dealer.

Dealer is essentially my neighbor, but hes on the roas all the time selling trailers. I hope he delivers here...